Emulate MMX maskmovq with SSE2 maskmovdqu for TARGET_MMX_WITH_SSE by
zero-extending source and mask operands to 128 bits.  Handle unmapped
bits 64:127 at memory address by adjusting source and mask operands
together with memory address.

	PR target/89021
	* config/i386/xmmintrin.h: Emulate MMX maskmovq with SSE2
	maskmovdqu for __MMX_WITH_SSE__.

From-SVN: r271234